The 18-year-old impressed as a substitute during the 2-0 win against Crystal Palace on his Premier League debut for United but is ineligible to face Bayer Leverkusen on Tuesday.

Moyes said that though the Belgian midfielder will also miss the trip to Shakhtar Donetsk, he will become available for United’s final four Champions League group games, because of Uefa’s registration system.

He said: "By October 7, Adnan will have been at the club for the length of time that will allow him to go onto the 'B' list. It means he will become a youth player [for the Champions League].

"If we had put him onto the 'A' list now, then we would never have been able to class him as a youth-team player. So we needed to wait for two games to do that."

Had Januzaj been on the A list, the United manager would have had to omit a senior player from his squad.

Januzaj has been linked with Manchester City but when asked whether he expected the youngster to agree a new deal, Moyes replied: "Yes."

United will also be without the suspended Nani for Leverkusen’s game at Old Trafford but could welcome back Shinji Kagawa, who sat out the Palace game.

Moyes added: "Shinji's better although he's still feeling symptoms in his throat. He's had a bit of flu as we said on Saturday. But he came in and did a bit of training yesterday [Sunday] and he's done a little bit today [Monday]. So he's feeling a bit better."

The Scot confirmed that Wayne Rooney will need to wear a headband again if he plays, but another United striker is out of the reckoning after Federico Macheda agreed to join Championship club Doncaster on loan.

The 22-year-old Italian scored on both of his first two league appearances for United in 2009 but has not found the net for them since 2011.